JAMA

Metered-dose inhalers drive billions in climate costs, study finds

October 8, 2025

Study details: A serial cross-sectional analysis examined greenhouse gas emissions from all inhalers approved for asthma and COPD in the U.S. between 2014 and 2024. Researchers used national outpatient dispensing data linked to validated emission estimates to quantify carbon dioxide equivalent (CO₂e) emissions and their social costs.

Results: Over 1.6 billion inhalers were dispensed, generating 24.9 million metric tons of CO₂e. Annual emissions rose 24% over the study period. Metered-dose inhalers (MDIs), which use hydrofluoroalkane propellants, accounted for 98% of emissions. Three products—albuterol, budesonide-formoterol, and fluticasone propionate—were responsible for 87% of the total. The estimated social cost of these emissions was $5.7 billion (range: $3.5–$10.0 billion).

Clinical impact: The findings highlight the environmental burden of MDIs and support efforts to shift prescribing toward lower-emission alternatives like dry powder and soft mist inhalers. Clinicians may consider environmental impact when selecting inhaler devices, especially for patients with multiple therapeutic options.

Source:

Feldman WB, et al. (2025, October 6). JAMA. Inhaler-Related Greenhouse Gas Emissions in the US: A Serial Cross-Sectional Analysis. https://pubmed.ncbi.nlm.nih.gov/41051742/